A fuel cell is an energy conversion device that converts chemical energy into electrical energy. The fuel cell generates electricity and heat by electrochemically combining a fluid fuel, such as hydrogen, carbon monoxide, or a hydrocarbon, and an oxidant, such as air or oxygen, across an ion-conducting electrolyte. The fuel cell generally consists of two electrodes positioned on opposite sides of an electrolyte. The oxidant passes over the oxygen electrode (cathode) while the fuel passes over the fuel electrode (anode), generating electricity, water, and heat.
A solid oxide fuel cell (SOFC) is constructed entirely of solid-state materials, utilizing an ion conductive oxide ceramic as the electrolyte. A conventional electrochemical cell in a SOFC comprises an anode and a cathode with an electrolyte disposed therebetween. In a typical SOFC, a fuel flows to the anode where it is oxidized by oxygen ions from the electrolyte, producing electrons that are released to the external circuit, and mostly water and carbon dioxide are removed in the fuel flow stream. At the cathode, the oxidant accepts electrons from the external circuit to form oxygen ions. The oxygen ions migrate across the electrolyte to the anode. The flow of electrons through the external circuit provides for consumable or storable electricity.
A SOFC stack operates at temperatures of about 600xc2x0 C. to 1,200xc2x0 C. Since the SOFC stack operates at high temperatures, it requires a large amount of time to heat up to efficient operating temperatures. In order to have a faster and more efficient startup, the SOFC stack can be pre-heated to reduce the time required to reach operating temperatures. However, the conventional methods of heating the SOFC do not evenly heat the SOFC stack. Conventional methods can include directing heated gases through the SOFC stack prior to startup. However, this method of pre-heating does not evenly heat the SOFC stack creating wide temperature gradients. The materials of the SOFC stack cannot handle the wide temperature gradients and thus, performance is hindered and damage to the SOFC stack can result.
The drawbacks and disadvantages of the prior art are overcome by the heated thin interconnect.
A solid oxide fuel cell stack is disclosed. The solid oxide fuel cell stack comprises an electrochemical cell having an electrolyte disposed between and in ionic communication with a first electrode and a second electrode. The solid oxide fuel cell stack also comprises at least one interconnect disposed in fluid and thermal communication with at least a portion of the electrochemical cell, the interconnect comprising an electrical supply connector.
A solid oxide fuel cell stack is disclosed. The solid oxide fuel cell stack comprises an electrochemical cell having an electrolyte disposed between and in ionic communication with a first electrode and a second electrode. The solid oxide fuel cell stack also comprises at least one interconnect disposed in fluid and thermal communication with at least a portion of the electrochemical cell, the interconnect comprising an electrical supply connector. A power supply is disposed in electrical communication with the electrical supply connector.
A method for heating a solid oxide fuel cell stack includes comprising disposing at least one interconnect in physical contact with at least a portion of an electrochemical cell having an electrolyte disposed between, and in ionic communication with, a first electrode and a second electrode. The at least one interconnect is independently heated.
The above described and other features are exemplified by the following figures and detailed description.